A top Iranian official's comments come as the first NATO-deployed Patriot missile batteries are declared operational along Turkey's border with Syria.

BEIRUT — Any foreign attack on Syria would be considered an attack on Iran, a senior Iranian official warned Saturday as the first Patriot missile batteries were declared operational along Turkey's tense border with Syria.

The North Atlantic Treaty Organization's decision to deploy six Patriot missile batteries in Turkish borderlands has rankled the Syrian government and its chief allies, Iran and Russia.

Tehran and Moscow view the move as a provocation that could escalate hostilities and widen the almost 2-year-old Syrian conflict. About 400 troops from the United States, Germany and the Netherlands are expected to accompany the Patriot batteries.

The comments Saturday by Ali Akbar Velayati, a top aide to Iran's supreme leader, Ayatollah Ali Khamenei, are among Tehran's strongest public declarations to date of support for Syrian President Bashar Assad, Iran's major ally in the Arab world.

Velayati noted Syria's crucial role in the "golden resistance chain" against Israel and the United States. The Iran-led "resistance" front includes Syria, Lebanon-based Hezbollah and the Palestinian group Hamas.

"An attack on Syria would be considered an attack on Iran and Iran's allies," Velayati was quoted as telling the semiofficial Mehr news agency.

Iran's defense minister, Ahmad Vahidi, also on Saturday warned against foreign intervention in Syria and assailed NATO's deployment of Patriot missiles as likely to bring "harmful consequences for the Syrian people," the official Islamic Republic News Agency reported.

NATO says the truck-mounted Patriots are strictly for defensive purposes, designed to protect Turkey from missiles fired from Syria. Turkish and NATO officials have repeatedly denied that the batteries will be used to create a no-fly zone in Syria that would block Damascus' devastating use of air power against rebel forces.

The Turkish-Syrian frontier, more than 500 miles long, has become deeply enveloped in the Syrian conflict. Opposition arms, supplies and personnel have infiltrated Syria from Turkey, enabling the rebels to seize large swaths of territory.

The Turkish military has fired retaliatory artillery rounds into Syria in response to what it says are Syrian shells landing on the Turkish side of the border. But there have been no reports of Syrian missiles landing in Turkish territory. The Patriots are meant to target incoming missiles, not artillery or mortar shells.

Iran's public coupling of its security with that of Syria highlights how the Syrian conflict has taken on the character of a regional proxy war. Russia and the United States have backed different sides in a reprise of their Cold War roles.

Providing material, logistics and economic support to Assad are his key foreign allies, Tehran and Moscow. The United States, meanwhile, has joined with Turkey, Saudi Arabia and other Western allies in bankrolling the political and military opposition seeking to topple Assad.

Despite their staunch public support of Assad, Iran's leaders are said to be involved in an intense closed-door debate about how to respond to the crisis in Syria and the possibility that Assad's government could collapse.

Last month, Tehran offered a Syrian peace plan that calls for negotiations and envisions Assad remaining in power at least until elections in 2014.

Some view the plan as a means of preserving Assad's power in the short-term while opening the way for his departure without a complete collapse of Syria's pro-Iran governing structure. In official pronouncements, however, Tehran has sought to project a public front unequivocally backing the Syrian president and rejecting any speculation that it was hedging its bets on Assad's survival.

Russia, likewise, has not publicly wavered in its dismissal of any move to sideline Assad. Russian Foreign Minister Sergei Lavrov last week accused the Syrian opposition of maintaining an "obsession with ousting Assad."

Opposition leaders responded that it was Moscow and Tehran that were obsessed with keeping Assad in power after almost two years of warfare that has left tens of thousands dead and much of the country in ruins.